Hole plug for oil and gas wells



, 2 Sheets-Sheet 1 Filed Oct. 24, 1959- I IVYE /V TOR. Giana-s M Moons, BY.

,1 I G. w. MOORE 2,291,742

HOLE PLUG FOR OIL- AND GAS WELLS Filed Oct. 24, 1939 2 Sheets-Sheet 2 INVENTOR. 0M5 M flooRs.

Patented Aug. 4, 1942 UNHTED STATES 2 Claims.

This invention relates to a hole plug for oil and gas wells, and particularly the type of plugs known as bottom hole, bridging, or heaving plugs.

An object of my invention is to provide a novel hole plug of the safety or signaling type, whereby the recovery of unusual or easily distinguishable material from the plug by a bailer or other clean-out tool will indicate to the operator that the Well has been cleaned, and that further use of the clean-out tools might cause serious injury to the bottom of the well.

A further object of my invention is to provide a novel hole plug for oil and gas wells, which is formed of a frangible and easily distinguishable material, so that striking of a cleanout tool against the plug will release particles of the plug material, these particles being drawn into the clean-out tools, will indicate to the operator that the well has been cleaned to bottom.

A further object is to provide a novel hole plug of the character stated, with a novel releasable or disengageable support, so that the plug may be left in the hole at the desired point.

Still another object is to provide a novel hole plug of the character stated, with novel means of engaging the wall or casing of the well so that the plug may be positioned at any point in the, well above bottom, if desired.

Still another object is to provide a novel hole plug of the heaving or bridging type, in which frangible or recoverable material is enclosed in a housing or casing, and with means provided engageable with the well casing to hold th plug fixedly at any point desired in the well.

Other objects, advantages and features of invention may appear from the accompanying drawings, the subjoined detailed description, and the appended claims.

In the drawings- Figure 1 is a longitudinal, sectional view of a bottom hole plug, embodying my invention.

Figure 2 is a sectional view taken on line 2-2 of Figure 1.

Figure 3 is a longitudinal, sectional view of a modified type of plug, embodying my invention.

Figure 4 is a sectional view taken on line 44 of Figure 3.

Figure 5 is a longitudinal, sectional view of another modified form of heaving plug, embodying my invention.

Figure 6 is a sectional view taken on line 66 of Figure 5.

Figure 7 is a longitudinal, sectional view of still another modified form of bridging or heaving plug, embodying my invention.

It is common oil field practice to close in the lower end of the liner of an oil well by cutting segments from the lower end of the liner and then folding these segments inwardly to form a closure. The reason for this closing of the liner is to prevent the material of the oil-producing formation from pushing upwardly into the liner during the operation of the well.

It is also common oil field practice to attach a closed metal shoe to the lower end of the liner. From time to time, it is necessary to shut down an oil well in order that quantities of sand, and the like, may be removed from the liner. These materials are carried into the liner through the slots or openings by the flow of oil. .To remove these materials, various types of clean-out bailers are lowered into the well on a cable, or other means, until the tool comes to rest on the material to be removed. The clean-out tool is then filled or loaded either by some mechanical means, or by raising and dropping the tool on the material. In any case, considerable weight is dropped on the material in the well while the cleanout tool is being filled. It frequently happens that due to a mistake in measurements or other misinformation, the operator will have cleaned out the liner to the bottom unknowingly and will continue to raise and drop the tool, thus subjecting the bottom of the liner or ,shoe to severe but unintended treatment, with the result that the liner or shoe will split or burst. When this has been done, sand or other material will be forced upwardly into the liner because of the flow of oil or gas, causing a great deal of difficulty.

Bridging and heaving plugs which are positioned in an oil well are also usual and wellknown in the art, but it is the purpose of my invention to provide a plug, either a bottom hole, bridging, or heaving, with a means of registering the existing well bottom and to prevent the unintentional rupturing of the lower pipe extremity by contact with well tools. This means of registering the existing well bottom is accomplished by forming the plug of a frangible or recoverable material, which is easily distinguishable by the operator, and thereby quickly indicating to him that bottom has been reached.

Referring first to Figures 1 and 2, which is particularly a bottom hole plug, my invention consists of an elongated, cylindrical body I formed of a frangible material, such as cement or the like, and which may be further distinguished by being colored with an insoluble coloring matter, or including unusual material, such as glass, the fragments of a bright metal, or the like. The cylindrical body I is substantially the same diameter as the well casing, and to permit fluid in the well to by-pass the plug in its downward movement, I provide longitudinally extending grooves or slots 2, in the periphery of the plug body. The plug is lowered to bottom by the supporting means 3, which consists of a bolt 4, which is fastened in the body I of the plug, and extends upwardly a suitable distance. The bolt 4 may be threaded or otherwisesecured in the body of the plug. A head 5 is provided on the upper end of the bolt 4. A sleeve 6 surrounds the bolt 4, and this sleeve includes a coupling 1, to which rods, a cable or the like are attached.

The lower end of the sleeve 6 issharpened, as shown at 8, for the purpose of cutting into the frangible or cementitious material of the body around the bolt 4. This cutting action is accomplished by bearing downwardly with the suspending rods or cable until the bottom of the bolt 4 is reached, then the bolt will break loose and the plug is left in the vhole resting n bottom. Since the plug is resting on the bottom of the liner or theshoe, no means is required to support or1hold the plug in the well.

In Figures 3 and 4, I have disclosed a bridging or heaving plu consisting of a substantially cylindrical body 9, which is preferably formed of a frangible, cementitious material, and preferably impregnated with aninsoluble coloring pigment. The lower end of the body 9 is encased in a sleeve l0, preferably metallic. The sleeve 10 is formed with inwardly tapered seats ll, upon which a plurality of slips [2 rest. Upwardmovement of the slips I2 is limitedby the shoulder I93. An outwardly tapered seating portion 1 4 is also provided on the sleeve 1 0, and slips l5 rest against this latter seat. A coil spring It bears against the bottom of the slips l5, and rests on .the shoulder I3, thus urging the slips [5 upwardlyon the seat [4. The upwardmovement of theslips i5 is limited by the following arrangement:

A bail 16 is attached ,to the plug by shear pins ll, substantially as shown in Figure 3. The lower end of this bail engages the slips .l5, as shown in Figure 3, thus holding these slips downwardly and retracted until the plug isready tobe set. Plates l8 hold the pins I l in the body ofthe plug until they are sheared, as will be furtherde, scribed. An eye IS on the bail l6 enables a suitable lowering means to be attached to the bail, such as cable and the like. In running the plug into the well, the natural dragof ,the slips 12 against the casing will hold these slips in an upward retracted position. When the point has been reachedwhere it is desired to setthe plug, .the cable which supports this plug 'is pulled up wardly and this sets the slips 12 into thecasing. Acontinued upward pull will then shear the pins ILand the bail l6 ispulled to the surface. The coil spring l6 now operates and pushes the slips l5 upwardly and outwardly to engage the-casing. The slips 12 thus prevent upward .movementol the plug, and the slips l5 prevent downward movement of the plug. It will be evident that the plug is thus fixedly held at any point in the casing against both upward or downward movement. An artificialor secondarybottom is thus provided for the well, this procedure transpiring where it is desired to abandon'the lower portion of a well or to redirect the holeto another di rection, .or to produce'from another formation.

In Figures. 5 and 6,:Ihave shown another modified type of heaving plug, which consists of an outer metallic sleeve 20. This sleeve is preferably closed at the bottom, as shown at 2|. The sleeve is filled with a frangible material, preferably cementitious, and might be colored as previously described, this inner cylindrical body being shown at 22. A slip ring 23 may be integrally formed with the sleeve 2!, or may be threadedly attached, as shown in Figure 5. The slip ring is provided with tapered seats 24, against which slips 25 rest. A shoulder 26 limits the upward movement of the slips 25. A bendable pin 21 is set in the slip ring 23 adjacent the upper end thereof, and this pin is rather loosely fit into the slip ring for purpose to be further stated. An eye 28 on the pin 21 enables a cable or the like to be attached thereto for .the purpose of lowering the plug into the well.

When the desired point in the well has been reached, an upward pull and upward movement of the plug will .set the slips ,25 into the casing,

,thus fastening the plug in position. Further upward pull on the lowering means will bend the pin 27 until it pulls out of the slip ring 23,

and thereafter the cable or other lowering means can be recovered from the well.

In Figure 7, I have disclosed a structure somewhat similar to that disclosed in Figure 5, with the .exception that suitable slips are provided to prevent both upward and downward movement of the plug. An outer cylindrical casing 29 encloses and retains the cementitious inner core 39. The slip ring 3| is provided with lower ta- .pered seats 32, against which the slips 3;3 bear. The upper slips 34 bear against the outwardly tapering seats 35. A bendable pin .36 extends through the wall of the slip ring 3l and into the slips 34. An eye 31 on the pin .36 is attachable to a cable, or the like, when lowering the plug into the well. A coil-spring 38 bears-against the bottom of the slips 3'4, and ur s these slips upwardly. To set the plug in the well, upward movement of the plug .on its supporting cable ,will set the slips 33 into the casing, thus preventing further upward movement of the plug. The supporting cable is now strained upwardly until thepin 36 bends and is pulled out of the slips 34 and the slip ring ,3l. Since the slips 34 are released, the sprin 38 will urge them upwardly and set them against the casing, thus holding the plug against downward movement. Since the .cable is released from the plug, it can now be reeled to the surface.

Having described my invention, I claim:

1. A .wellplug consisting of .a body of frangible material, a pin imbedded inthamaterial and-rising from the top thereof, lowering meansengaging the pin, said lowering means being longitudinally movable on the pinand adapted .and arranged to breakthe frangible material ,to release the pin from the body of said frangible material.

2. A well plug consisting of a body of frangible material, a pinimbedded in the materialandwising from the top thereof, .lowering means en.- gaging the pin, said lowering means being ,longitudinally movable on the pin and adapted-and arranged to break the frangible material .to release .thepin from the body of said frangible material, said frangible material being impregnated with a coloring matter.

GEORGE W. -MOORE. 

